CZ305110B6 - Bimetallic material - Google Patents

Abstract

In the present invention, there is disclosed a bimetallic material, particularly a bimetallic material for working implements of agricultural machines, the bimetallic material comprising a wearable layer formed by a wear-resistant boron steel containing 0.10 to 0.30 percent by weight of carbon C, 0.20 to 0.80 percent by weight of silicon Si, 0.50 to 1.70 percent by weight of manganese Mn, 0 to 0.025 percent by weight of phosphorus P, 0 to 0.015 percent by weight of sulfur S, 0.10 to 1.50 percent by weight of chromium Cr, 0 to 1.50 percent by weight of nickel Ni, 0 to 0.60 percent by weight of molybdenum Mo and 0.0005 to 0.005 percent by weight of boron B, wherein the balance being iron Fe, and a supporting layer consisting of structural fine-grained steel containing 0.1 to 0.20 percent by weight of carbon C, 0 to 0.55 percent by weight of silicon Si, 0 to 1.60 percent by weight of manganese, 0 to 0.040 percent by weight of phosphorus P and 0 to 0.45 percent by weight of sulfur S, wherein the balance being iron Fe, wherein the wearable layer and the supporting layer being coupled together by forging.

Description

Bimetallic material

Technical field

BACKGROUND OF THE INVENTION The present invention relates to bimetallic material for the production of agricultural machine tools, in particular agricultural machine tools for tillage and seeding, where sufficient abrasion and impact resistance is required.

BACKGROUND OF THE INVENTION

A number of solutions are known from the prior art for the protection of wear tools of agricultural machines. Working tools moving in the soil are subject to high shocks and wear, which makes them less durable.

Working tools gradually wear out over their lifetime and change in thickness and geometry. The geometry change is so significant that at a certain stage of wear, the working tool no longer performs the required work in the soil and needs to be replaced. At the time of replacement, the worn tool usually still has about 30 to 70% of its original weight, but is no longer usable.

The basic form of protection of working tools against wear is to increase the hardness of the basic material of the whole tool or its working part by heat treatment, most often by hardening. This protection is both insufficient and relatively expensive.

Another option is to protect the most exposed parts of the tool with abrasion-resistant, most often carbide inserts fixed by soldering. Abrasion resistant inserts are attached to the parts of the agricultural machine's working tools that are most exposed to abrasion in the soil. Such solutions are known, for example, from the international patent applications WO 2012007470 and WO 2010149464. This method has disadvantages in the difficulty of the brazing process and in the difficulty of using more complex plate geometries. The main disadvantage is also the heating of the workpiece blank during brazing in the area larger than that covered by the insert and thereby reducing its hardness, tempering of the turbid material, which results in a greater susceptibility to wear in the region behind the insert and thereby reduced tool life. A great disadvantage of this solution is also the high cost of the entire soldering process and the solder material.

Welding the carbide material to the exposed area is another way of protecting the tool from wear. The disadvantage is that the workpiece blank is heated and thus the hardness of the base material is reduced, which results in the above-mentioned greater susceptibility of the support part to wear and thus a reduced tool life. A big disadvantage is again the high cost of the entire surfacing process.

The most common material for the production of agricultural machine tools is currently steels with a relatively low carbon content (0.25 to 0.35% by weight) and a low boron content (max. 0.005% by weight). These steels are well heat treatable and show very good abrasion resistance after heat treatment. The disadvantage of these steels is the higher price compared to standard fine-grained structural steels.

After wearing tools made of wear-resistant boron steels, a considerable part of the tool remains, which has no further use. This part was made of the same quality abrasion-resistant material with a higher purchase price and thus increases the overall operating costs of the agricultural machine. This is a major drawback of the present prior art solution.

- 1 GB 305110 B6

The object of the invention is to find a suitable material for the production of agricultural machine tools, to eliminate the disadvantage described above and to reduce the cost of the unusable remainder of the machine tool after its wear.

SUMMARY OF THE INVENTION

The above-mentioned deficiencies are largely eliminated and the objects of the invention are fulfilled by a bimetallic material, in particular a bimetallic material for agricultural working tools, according to the invention, comprising a wear layer consisting of wear-resistant boron steel containing 0.10 to 0.30 wt. % C, 0.20-0.80 wt. Si, 0.50 to 1.70 wt. % Mn, 0 to 0.025 wt. % P, 0 to 0.015 wt. % S, 0.10 to 1.50 wt. Cr, 0 to 1.50 wt. % Ni, 0 to 0.60 wt. % Mo, and 0.0005 to 0.005 wt. B, the remainder being iron Fe and a backing layer consisting of fine-grained structural steel containing 0.1 to 0.20 wt. % C, 0 to 0.55 wt. % Si, 0 to 1.60 wt. % Mn, 0 to 0.040 wt. % P, and 0 to 0.045 wt. S, the remainder being iron Fe, which are joined by forging.

It is very advantageous that the bimetallic material is heat treated by quenching after its forging and, after quenching, heat treated by tempering to increase toughness. This is advantageous for working tools that will be highly stressed by stone shocks when working in extremely abrasive stony soils.

In a preferred embodiment, the thickness of the wear layer is 30 to 70% of the total thickness of both layers.

The bimetallic material according to the invention is advantageously usable for the production of wear tools of agricultural machines, in particular of tillage and sowing machines. The advantage of this solution is the low material cost of the part of the tool that does not wear during operation and is thrown away as a remainder at the end of its service life. The optimum thickness of the residual part after wear is determined individually for each type of work tool. Therefore, the ratio of the thickness of the wear-bearing layer of the bimetallic material can be appropriately selected for each type of tool.

With a suitably selected production technology, the production of the working elements using the bimetallic material according to the invention results in very small extra costs, which, however, are compensated by significant material savings and a reduction in the total manufacturing cost of the final work tools.

The use of the bimetallic material according to the invention in the production of agricultural machine tools therefore reduces material costs and the cost of production while maintaining the normal life of the agricultural machine tools.

DETAILED DESCRIPTION OF THE INVENTION

The bimetallic material for agricultural machine tools comprises a wear and carrier layer which is joined by forging, after which it is heat treated by quenching and after tempering it is heat treated by tempering to increase toughness.

The wear layer consists of wear-resistant boron steel containing 0.10 to 0.30 wt. % C, 0.20-0.80 wt. Si, 0.50 to 1.70 wt. % Mn, 0 to 0.025 wt. % P, 0 to 0.015 wt. % S, 0.10 to 1.50 wt. Cr, 0 to 1.50 wt. % Ni, 0 to 0.60 wt. % Mo, and 0.0005 to 0.005 wt. B, the remainder being iron Fe.

-2GB 305110 B6

The backing layer consists of a fine-grained structural steel containing 0.1 to 0.20 wt. % C, 0 to 0.55 wt. % Si, 0 to 1.60 wt. % Mn, 0 to 0.040 wt. % P, and 0 to 0.045 wt. S, the remainder being iron Fe.

The thickness of the wear layer is 30 to 70% of the total thickness of the two layers.

Industrial applicability

The bimetallic material according to the invention can be used in the industrial production of wear tools for agricultural machines, in particular for tillage and seeding machines.

PATENT CLAIMS

Claims (4)

Bimetallic material, in particular bimetallic material for agricultural machine tools, characterized in that it comprises a wear layer consisting of wear-resistant boron steel containing 0.10 to 0.30% by weight. % C, 0.20-0.80 wt. Si, 0.50 to 1.70 wt. % Mn, 0 to 0.025 wt. % P, 0 to 0.015 wt. % S, 0.10 to 1.50 wt. Cr, 0 to 1.50 wt. % Ni, 0 to 0.60 wt. % Mo, and 0.0005 to 0.005 wt. B, the remainder being Fe, and a structural layer consisting of fine-grained structural steel containing 0.1 to 0.20 wt. % C, 0 to 0.55 wt. % Si, 0 to 1.60 wt. % Mn, 0 to 0.040 wt. % P, and 0 to 0.045 wt. S, the remainder being iron Fe, which are joined by forging. Bimetallic material according to claim 1, characterized in that it is heat treated by quenching. Bimetallic material according to claim 2, characterized in that after quenching, it is heat treated by tempering to increase toughness. Bimetallic material according to any one of the preceding claims, characterized in that the thickness of the wear layer is 30 to 70% of the total thickness of the two layers. End of document